1. Field of the Invention
The present invention relates to a catheter, and more specifically to a catheter which exhausts a humor such as a hematoma, a brain fluid, and an encephalophyma smoothly without any infection, and be able to inject a hematoma resolvent while maintaining a constant brain pressure, and is inserted into an accurate operative portion in the cranial cavity using a brain stereotactic frame conveniently and easily.
2. Description of the Prior Art
An intracranial hematoma has been treated by a therapy that directly removes it through a craniotomy which is a kind of a neurosurgical operation. Recently, a therapy has been widely used that removes the intracranial hematoma directly or by a brain stereotactic frame by using a brain cross section radiography or a magnetic resonance (MR) radiography using a computer. Since the operation can be performed under a local anesthesia in a short time, this therapy is applied to patients who cannot be under a general anesthesia.
For example, in the case that a brain parenchyme has a hemorrhage therein, a location of a hematoma in a cranial cavity is exactly measured by a brain cross section radiography. A skull is perforated, and a catheter is inserted into the hematoma directly or by using the brain stereotactic instrument in order to exhaust the hematoma out of the cranial cavity therethrough.
An exhaust aspect of the hematoma depends on a condition of the hematoma (i.e., solidity or liquidity). The hematoma should be exhausted steadily rather than momentarily, and the catheter may remain in the cranial cavity for a period of days in order to steadily exhaust the remaining hematoma out of the cranial cavity therethrough. In particular, In case of a solid hematoma, a hematoma resolvent is injected into the hematoma through the catheter so that the hematoma may be easily exhausted.
FIG. 1 is a cross-sectional view illustrating a conventional catheter. The catheter 1 includes a long tube 2 in which an exhausting passage 2a is formed, a head portion 3 attached to one end of the tube 2, and a plurality of holes 4 formed in a portion of the tube 2 near to the head portion 3. The catheter 1 further includes a location indication scale (not shown) arranged in a longitudinal direction thereof.
The catheter 1 is made of a transparent, atoxic, and flexible material, and preferably made of a pure silicone rubber.
The tube 2 is inserted into the cranial cavity through a perforated portion of the skull (not shown) by a depth to place the head portion 3 in a central portion of a humor such as a hematoma and a tumor. The rest portion of the tube 2 passes through the perforated portion of the skull and is put at a distance of 3 cm to 4 cm under the scalp by use of a trocar.
The outer end of the cranial cavity of the tube 2 is coupled to a brain pressure controller (not shown) and to a humor collecting bursa (not shown), so that the humor in the cranial cavity flows out and is collected in the humor collecting bursa in state of being excluded from outside.
The head portion 3 and a radiation construction line 5 of a radiation construction material are to grasp a location of the catheter 1 inserted into the cranial cavity during a plain roentgenography for the skull.
However, the catheter 1 of FIG. 1 has the following disadvantages in that the catheter 1 has one exhausting passage 2a. In the case that there is a need for injecting a hematoma resolvent or a physiological salt solution, a humor such as a hematoma filled in the catheter has to be inserted into the cranial cavity again. Further, since the physiological salt solution has to be injected additionally by an inside volume of the catheter 1, a brain pressure is increased. Furthermore, there is a risk of an infection due to a repeated injection of the physiological salt solution, and the catheter 1 is inconvient to manipulate.
In efforts to overcome the problems descibed above, Korean Patent No. 178113 discloses a catheter that the hematoma resolvent is easily injected without increasing the brain pressure, and the humor such as the hematoma filled in the catheter is not outflowed into the cranial cavity again, and thus there is no risk of an infection.
FIG. 2 is a cross-sectional view illustrating a catheter of Koean Patent No. 178113.
The catheter 10 includes a long tube 12, a head portion 13 attached to one end of the tube 12, a plurality of holes 14 formed in a portion of the tube 12 near to the head portion 13, and a location indication scale 15.
The tube 12 includes an exhausting tube 12a and an injection tube 12b. The exhausting tube 12a has a relatively large cross-section area. A humor in the cranial cavity is exhausted through the exhausting tube 12a. The injection tube 12b has a relatively small cross-section area. A hematoma resolvent is injected into the cranial cavity through the injection tube 12b. A through hole 13a is formed in the head 13 to communicate with the injection tube 12b. 
An injection tube 16 is removably coupled to one end portion of the injectin tube 12b opposite to the head portion 13. The injection tube 16 has the same diameter as the injection tube 12b and thus communicates with the injection tube 12b. 
A coupling member 17 is arranged to seal and secure a coupling portion between the injection tubes 12b and 16. The coupling portion between the injection tubes 12b and 16 is at a distance from the head portion 13 to be located outside the cranial cavity when the head portion 13 is located in the cranial cavity and the tube 12 is extended externally during a use of the catheter 10.
The injection tube 16 is separateed from the tube 12 and is cut to have a free end (not shown) when used. However, the injection tube 16 is manufactured to be coupled to the tube 12 by the coupling member 17 for the sake of custody and a surgerical convenience.
Another coupling member 18 couples the tube 12 to a tube 19 attached to a rear portion of the tube 12. One end of the injection tube 16 is inserted into an inner surface of the coupling member 18.
However, in the conventional catheter 10, the tube 12, the injection tube 16 and the coupling members 17 and 18 are configured to surround an outer circumference surface of the tubes 12 and 19. As a result, at least the coupling portion of the catheter 10 has an external diameter larger than those of the tubes 12 and 19.
Therefore, in case that a brain parenchyme has a hemorrhage therein, after measuring a location of the hematoma in the cranial cavity using the cross section radiography for a brain to perforate the skull, it is very difficult to insert the catheter 10 into the hematoma using a brain stereotactic frame (not shown).
In more detail, the brain stereotactic frame helps to determine an accurate location of the hematoma in the cranial cavity. But, a coupling portion of the catheter 10 corresponding to the injection tube 16 and the coupling members 17 and 18 has an external diameter larger than the tube 12. As a result, a through hole, which is formed by the brain stereotactic frame in order to prevent the catheter from being separated and has the almost same diameter as the tube 12, becomes narrow relatively due to the injection tube 16 and the coupling members 17 and 18. Consequently, the brain stereotactic frame becomes difficult to use, and a high skill is required to place the catheter in an accurate location.
In addition, it becomes very difficult to perforate the skull hypodermis layer using a trocar due to the injection 16 and the coupling members 17 and 18. Furthermore, since the conventional catheter has a complicated dual-tube structure, an inferiority rate is high, a cleaning and a sterilization are not easy, and a manufacturing cost is high.